Die-stock.



F. W. SMITH, JR.

DIE STOCK.

APPLICATION FILED JAN. 26. I916.

Patented Oct. 24, 1916.

77/ ff/m -5 I g/l/ M01012? INVENTOR To all whom it may concern:

pnrrap j sra'rns arana QFFICE- FRIEND w. sMITII, an; or

BRIDGEPORT, CONNECTICUT, ASSIGNOR TO LEWIS CURTIS,

OF BRIDGEPORT, CONNECTICUT.

- DIE-STOCK.

Be it known that I, FRIEND W. SMITH, J r., a citizen of the United States, residing at the city of Bridgeport, in the county of Fairfield, State of Connecticut, have invented certain new and useful Improvements in Die- Stocks; and I do declare the following tobe a full, clear, and exact description of the inventicn, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to screw thread cutting. but particularly has reference to die stocks for cutting threads on a taper.

The principal object of the invention is to provide a taper thread cutting machine in which there shall be no receding movements of the dies caused by the contact of the heel ends of the latter with a fixed inclined surface, since in my improvement the dies at their heel ends abut against levers which latter are themselves caused to swing outwardly during the thread cutting operation thus permitting the receding movementsof the dies. 7

In producing a machine capable of carrying out the objects of this invention as generally stated above, it will be understood that the same is susceptible of changes in details of structural arrangement, one simple and practical embodiment thereof being shown in the accompanying drawing where- Figure 1 is a front elevation of a die stock constructed in accordance with my improvement. Fig. 2 is a section at the line 2-2 of Fig. 1. Fig. 3 is a section at the line 3-3 of Fig. 2. Fig. 4 is a broken sectional elevation similar to Fig. 2 but showing the position which the parts assume at the completion of the taper threading. and Fig. 5 is a broken sectional elevation similar to Fig. 2 but showing a modification of my improvement.

Similar numerals of reference denote like parts in the several figures of the drawing.

1 is the work holder to which the work is secured by means of clamping screws 2 or in any other suitable manner, said holder being interiorly threaded as shown at 3.

4 is the die carrying member having on its inner end an exterior thread 5 which engages the thread 3 in the manner usual in machines of this description.

' 6 are, the dies or Chasers which are slidably arranged within suitable guide ways in the member 4 in the usual manner, and 7 is a keeper plate secured to the face of the paember 4 whereby the dies are held in posi- 8 are guide ways formed within the memher 4, preferably by means of spaced fingers 9 extending radially from the circumference of said member at points in line with the dies.

10 is a ring which is journaled around the work holder loso as to be capable of free rotation, and 11 is a keeper ring which is secured to the inner face of the work holder 1 and overlaps the ring 10 so as to hold the latter in position.

12 are levers whose inner ends are movably connected to the ring 10, preferably by pivot p1ns'13 extending through spaced ears 14 that extend from the ring, and within these levers are elongated inclined slots 15. The outer'extremities of these levers 12 extend within the guide ways 8 in the immediate rear of the heel ends of the dies 6 so as to afford abutments for said ends, and studs 16 driven through the fingers 9 extend within the inclined slots 15, so that it will be clear that when the die carrying member moves inwardly along the work holder, the studs 16 will travel within the slots 15 and thereby gradually swing the levers 12 outwardly so as to permit the gradual receding movements of the dies during the taper threading. Sockets 17 for the reception of the usual hand levers may extend from the die carrying member so that the latter may be manipulated by hand, if desired. The inner ends of the slots 15 are abruptly deflected as shown at 18, in order to afiord quick release of the dies in the usual manner, there being nothing novel in my invention in this respect.

Referring to Fig. 5 I have shown a modified form of my improvement in which the lever 12 has an inclined surface 19 along its outside edge while the stud 16 driven through the fingers 9 engages this surface, so that as the die carrying member advances inwardly the lever will gradually swing outwardly as the stud travels along different parts of the incline thereby permitting the receding movements of the dies.

I therefore do not wish to be limited to the exact location of the inclined surface so I Specification of Letters Patent. Patented (131324,, 1916. I Application filed January as, 1916. 7 Serial n. 74,315. i i

long as the latter is not at the inner edge of the. leversso as to have immediate contact with the heel ends of the dies.

.Having thusdescribed my invention what I'claim as new and desire to secure by Letters Patent is:

1. In a machine of the'character described, the combination with the die carrying member *flllddillfi WOlk holder slidably disposed withrespect to each other, of the thread cutting dies slidably carried by said member, a ring rotatably journaled ZIIOLHIClQthQWOlk holder, levers whose inner ends arepivot'ed to, said ring and against whoseouter ends said dies abut, said levers having inclined surfaces whichdo not contact said dies, and means carried by said member and engaging said inclined surfaces whereby as said membermoves inwardly along the work holder the levers will graduallyswing outwardly and thereby permitthe dies to recede durt, ing the thread cutting operations.

her and the '2; In a machine of the character described, the combination with the die carrying memwork holder having a screw thread connection with each other,.of thread cutting dies slidably carried by said mem- "ber, a ring rotatably secured to the work holder, levers movably connected at their in- 0 ner ends with said. ring and having their outer ends free and extending within guideways in said member and aflording abutments for the heel ends of said dies, said lefor swinging the lever outwardly as the die.

carrying me work holder.

.4. Ina machine of the character described, I

a work holder, a die car'rving member movable toward the holder, a die slidable out-.

wardly in the member, a lever pivoted to the holder and engaging with the outer end of the die, the latter being movable with the carrying member longitudinally of and relative to thelever, and means for swinging the lever outwardly as the die carrying. member is moved toward the work holder.

In testimony whereof I afiix my signature in presence of two witnesses.

FRIEND w. SMITH, JR. Witnesses M. T. LoNennN, EMILY liionmsou.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

' Washington, D. O.

mber is advanced-toward the 

